The present invention is directed to a clamping mechanism in a socket formed by a hollow clamping sleeve which will hold a tool shaft of a dental tool. The clamping sleeve adjacent an end facing away from the tool has longitudinally extending slots so that the portion of the sleeve forms resilient tongues for retaining the tool shaft in a clamped position. In addition, the sleeve can be moved to a releasing position by a manipulator or button being pressed to engage a plunger which has an outwardly tapering surface engaging internal tapered or conical surfaces of the fingers.
U.S. Pat. No. 4,874,314, whose disclosure is incorporated herein by reference thereto and which claims priority from German Patent Application 36 44 055, discloses a clamping arrangement to hold a dental tool in a dental handpiece. The arrangement includes a hollow sleeve having slots adjacent an end facing away from the tool to form resilient fingers or tongues, which will engage a cylindrical surface of the tool. Each of the fingers has inwardly tapering surfaces engageable by corresponding tapering surfaces of a plunger which can be axially moved to cause the fingers to disengage the shaft of the tool. In this clamping mechanism, the plunger can be actuated by a manipulator and also assumes the guidance of the tool shaft. Since the plunger should be freely movable in an axial direction as a result of its function, an imprecise guidance of the tool shaft having untrue running of the tool can occur, particularly given an imprecision in the manufacture and fit. Higher running noises, as well as increased wear on the parts, will result from these imprecise fits. Increased wear, in particular, can also be attributed to the fact that the plunger is not secured against torsion.